1. Field of the Invention
This invention relates to an apparatus which utilizes corona discharge to remove fine particles from the exhaust gas of an engine or the like by causing the particles to associate with charged droplets.
2. Prior Art Statement
In Japanese Patent Public Disclosure No. 62-19262, the present inventor disclosed a method of removing fine particles of ash, soot and the like contained in a flow of gas, such as exhaust gas. The disclosed method comprised providing a hollow needle electrode in the flow of exhaust gas, delivering a liquid via this hollow electrode, applying a high voltage between this hollow electrode and an opposing cylindrical electrode to atomize the liquid coming from the hollow electrode and spraying the atomized droplets into the exhaust gas flow to thereby capture the particles in the exhaust gas, and then collecting the droplets.
The method of removing particles according to the disclosure is effective for capturing particles that have a high electrical resistance, or when there is a relatively small potential difference across the electrodes. However, when the particles to be removed have a low electrical resistance, such as soot, shorting can by produced between the electrodes by particles adhering to the inside wall of the flow channel, or by the space between the electrodes becoming filled with gas in which there is a high particle concentration. Thus, the method has been accompanied by problems such as the need to specify the particles to be collected, and limitations on the potential difference across the electrodes.
The object of the present invention is to provide an apparatus for removing fine particles from exhaust gas which utilizes the adsorption effect of charged droplets to capture the particles in the exhaust gas, and which is able to effectively remove and collect the particles on a continuous basis without shorting, even when the particles concerned have a low electrical resistance.